The present invention relates to an agricultural row marker. A row marker is typically used with a planter system to indicate to a farmer where his tractor should be traveling relative to planted rows so that the rows being planted during one pass of the planter will be properly spaced from those already planted on a previous pass.
Planter systems include a number of individual planting units which are mounted on a cross frame. The frame may either be of a pull type (in which most of the weight of the frame and units is separately borne by support wheels), or of a tool bar type (in which the frame and units are connected to a conventional three-point hitch for raising and lowering the planter system). The present invention applies to both structures, and the term "planter frame" is therefore intended to include both.
There has been a recent trend to larger and larger planters--that is, whereas previously, commercially available planters were limited to twelve-row widths, larger tractors and larger farms have made it desirable to use planters of even greater width. A folding planter frame disclosed in my copending application Ser. No. 644,547, filed Dec. 29, 1975, now abandoned, entitled "Agricultural Tool Bar", makes it possible to plant as many as 25 rows simultaneously, with a three-foot spacing between rows. It will thus be appreciated that the complete planter frame, when unfolded to the use position, may extend for a length of 35-80 feet. When a farmer makes one pass with such a planter, the outermost units will be planting rows approximately 40 feet from his position. On the next pass, he will be sitting 80 feet to that side (that is, in the middle of the next pass), and this makes it desirable that the marker be located a full planter width from his position at the seat of the tractor (that is, one-half of the planter width for the pass presently being planted, and another half of the planter width for the pass to be planted). In other words, the marker should have a length, in the use position, equal to one-half of the width of the planter frame when it is extended (i.e. the distance from the center line of the tractor to the outermost planting unit).
In the past, one form of marker included two arms pivotally joined together and having a marker element on the outboard end of one of the arms, with the inboard end of the other arm pivotally connected to the end of a planter frame. Ordinarily, a planter has separate markers on its right and left sides. In these markers, in the folded position, the two arms extend upwardly. With the trend toward larger planters, the height of such systems, added to the height of a planter frame, makes it prohibitive. Systems have been suggested for rotating the folded marker arms over the planter frame sideways, but the only commercial system for doing so of which I am aware requires two separate hydraulic rams for complete operation.
One of the principal functions of this invention is to provide a marker capable of extending up to 40 feet or farther to the side of a planter frame in the use position, yet extending a height of less than about 12 feet in the folded or road travel position, wherein complete operation is effected through the use of a single hydraulic cylinder and piston rod unit (or simply "hydraulic ram").
In the larger system disclosed, a pair of folding arms carry a marking element; and the inner arm is pivotally mounted to a short boom which, in turn, is pivotally mounted to the outboard end of a planter frame and adapted to be moved between a horizontal use position and upright storage or road travel position. A single hydraulic ram is connected between the planter frame and the intermediate arm to fold and unfold the marker.
To fold the marker for road travel, the ram is actuated in a first direction; and during a first portion of the ram's movement, the arms fold by cranking the intermediate arm about its pivotal connection to the short boom. After the intermediate arm has reached an upright position, further ram action continues, and this further action folds the boom from its horizontal position to its upright position to place the folded intermediate and outer arms over the planter frame.
To unfold the marker for use, the ram is actuated in the reverse direction. During the first portion of the unfold cycle, the short boom is rotated to its horizontal position. As the reverse ram action continues, after the short boom is lowered, the arms are unfolded to the horizontal position for use.
Because of the length of the marker, a support wheel may be provided, preferably at the juncture between the intermediate and outer arms. Further, stops are provided at a number of locations. A first stop limits the folding rotation of the intermediate arm relative to the short boom. Additional stops are provided for the two limit positions of the short boom.
A smaller version is also disclosed using only a single arm, for smaller planters.
Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment wherein identical reference numerals will refer to like parts in the various views.